DetailsViewModeEventHandler Delegar
Definição
Importante
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Representa o método que manipula o evento ModeChanging de um controle DetailsView.
public delegate void DetailsViewModeEventHandler(System::Object ^ sender, DetailsViewModeEventArgs ^ e);public delegate void DetailsViewModeEventHandler(object sender, DetailsViewModeEventArgs e);type DetailsViewModeEventHandler = delegate of obj * DetailsViewModeEventArgs -> unitPublic Delegate Sub DetailsViewModeEventHandler(sender As Object, e As DetailsViewModeEventArgs)Parâmetros
- sender
- Object
A fonte do evento.
Um DetailsViewModeEventArgs que contém os dados do evento.
Exemplos
O exemplo de código a seguir demonstra como adicionar programaticamente um DetailsViewModeEventHandler delegado ao ModeChanging evento de um DetailsView controle.
<%@ Page language="C#" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">
void Page_Load(Object sender, EventArgs e)
{
// Create a new DetailsView object.
DetailsView customerDetailsView = new DetailsView();
// Set the DetailsView object's properties.
customerDetailsView.ID = "CustomerDetailsView";
customerDetailsView.DataSourceID = "DetailsViewSource";
customerDetailsView.AutoGenerateRows = true;
customerDetailsView.AutoGenerateEditButton = true;
customerDetailsView.AllowPaging = true;
customerDetailsView.DataKeyNames = new String[1] { "CustomerID" };
// Programmatically register the event-handling method
// for the ItemInserted event of a DetailsView control.
customerDetailsView.ModeChanging += new DetailsViewModeEventHandler(this.CustomerDetailsView_ModeChanging);
// Add the DetailsView object to the Controls collection
// of the PlaceHolder control.
DetailsViewPlaceHolder.Controls.Add(customerDetailsView);
}
void CustomerDetailsView_ModeChanging(Object sender, DetailsViewModeEventArgs e)
{
// Use the sender parameter to access the DetailsView
// control that raised the event.
DetailsView customerDetailsView = (DetailsView)sender;
// Use the NewMode property to determine the mode to which the
// DetailsView control is transitioning.
switch (e.NewMode)
{
case DetailsViewMode.Edit:
// Hide the pager row and clear the Label control
// when transitioning to edit mode.
customerDetailsView.AllowPaging = false;
MessageLabel.Text = "";
break;
case DetailsViewMode.ReadOnly:
// Display the pager row and confirmation message
// when transitioning to edit mode.
customerDetailsView.AllowPaging = true;
if (e.CancelingEdit)
{
MessageLabel.Text = "Update canceled.";
}
else
{
MessageLabel.Text = "Update completed.";
}
break;
case DetailsViewMode.Insert:
// Cancel the mode change if the DetailsView
// control attempts to transition to insert
// mode.
e.Cancel = true;
break;
default:
MessageLabel.Text = "Unsupported mode.";
break;
}
}
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>DetailsViewModeEventHandler Example</title>
</head>
<body>
<form id="form1" runat="server">
<h3>DetailsViewModeEventHandler Example</h3>
<!-- Use a PlaceHolder control as the container for the -->
<!-- dynamically generated DetailsView control. -->
<asp:PlaceHolder id="DetailsViewPlaceHolder"
runat="server"/>
<br/><br/>
<asp:label id="MessageLabel"
forecolor="Red"
runat="server"/>
<!-- This example uses Microsoft SQL Server and connects -->
<!-- to the Northwind sample database. Use an ASP.NET -->
<!-- expression to retrieve the connection string value -->
<!-- from the web.config file. -->
<asp:sqldatasource id="DetailsViewSource"
selectcommand="Select [CustomerID], [CompanyName], [Address],
[City], [PostalCode], [Country] From [Customers]"
updatecommand="Update [Customers] Set
[CompanyName]=@CompanyName, [Address]=@Address,
[City]=@City, [PostalCode]=@PostalCode,
[Country]=@Country
Where [CustomerID]=@CustomerID"
connectionstring=
"<%$ ConnectionStrings:NorthWindConnectionString%>"
runat="server"/>
</form>
</body>
</html>
<%@ Page language="VB"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">
Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs)
' Create a new DetailsView object.
Dim customerDetailsView As New DetailsView()
' Set the DetailsView object's properties.
customerDetailsView.ID = "CustomerDetailsView"
customerDetailsView.DataSourceID = "DetailsViewSource"
customerDetailsView.AutoGenerateRows = True
customerDetailsView.AutoGenerateEditButton = True
customerDetailsView.AllowPaging = True
Dim keyArray() As String = {"CustomerID"}
customerDetailsView.DataKeyNames = keyArray
' Programmatically register the event-handling method
' for the ItemInserted event of a DetailsView control.
AddHandler customerDetailsView.ModeChanging, AddressOf CustomerDetailsView_ModeChanging
' Add the DetailsView object to the Controls collection
' of the PlaceHolder control.
DetailsViewPlaceHolder.Controls.Add(customerDetailsView)
End Sub
Sub CustomerDetailsView_ModeChanging(ByVal sender As Object, ByVal e As DetailsViewModeEventArgs)
' Use the sender parameter to access the DetailsView
' control that raised the event.
Dim customerDetailsView As DetailsView = CType(sender, DetailsView)
' Use the NewMode property to determine the mode to which the
' DetailsView control is transitioning.
Select Case e.NewMode
Case DetailsViewMode.Edit
' Hide the pager row and clear the Label control
' when transitioning to edit mode.
customerDetailsView.AllowPaging = False
MessageLabel.Text = ""
Case DetailsViewMode.ReadOnly
' Display the pager row and confirmation message
' when transitioning to edit mode.
customerDetailsView.AllowPaging = True
If e.CancelingEdit Then
MessageLabel.Text = "Update canceled."
Else
MessageLabel.Text = "Update completed."
End If
Case DetailsViewMode.Insert
' Cancel the mode change if the DetailsView
' control attempts to transition to insert
' mode.
e.Cancel = True
Case Else
MessageLabel.Text = "Unsupported mode."
End Select
End Sub
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>DetailsViewModeEventHandler Example</title>
</head>
<body>
<form id="form1" runat="server">
<h3>DetailsViewModeEventHandler Example</h3>
<!-- Use a PlaceHolder control as the container for the -->
<!-- dynamically generated DetailsView control. -->
<asp:PlaceHolder id="DetailsViewPlaceHolder"
runat="server"/>
<br/><br/>
<asp:label id="MessageLabel"
forecolor="Red"
runat="server"/>
<!-- This example uses Microsoft SQL Server and connects -->
<!-- to the Northwind sample database. Use an ASP.NET -->
<!-- expression to retrieve the connection string value -->
<!-- from the web.config file. -->
<asp:sqldatasource id="DetailsViewSource"
selectcommand="Select [CustomerID], [CompanyName], [Address],
[City], [PostalCode], [Country] From [Customers]"
updatecommand="Update [Customers] Set
[CompanyName]=@CompanyName, [Address]=@Address,
[City]=@City, [PostalCode]=@PostalCode,
[Country]=@Country
Where [CustomerID]=@CustomerID"
connectionstring=
"<%$ ConnectionStrings:NorthWindConnectionString%>"
runat="server"/>
</form>
</body>
</html>
O exemplo de código a seguir demonstra como adicionar declarativamente um DetailsViewModeEventHandler delegado ao ModeChanging evento de um DetailsView controle.
<%@ Page language="C#" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">
void CustomerDetailsView_ModeChanging(Object sender, DetailsViewModeEventArgs e)
{
// Use the NewMode property to determine the mode to which the
// DetailsView control is transitioning.
switch (e.NewMode)
{
case DetailsViewMode.Edit:
// Hide the pager row and clear the Label control
// when transitioning to edit mode.
CustomerDetailsView.AllowPaging = false;
MessageLabel.Text = "";
break;
case DetailsViewMode.ReadOnly:
// Display the pager row and confirmation message
// when transitioning to edit mode.
CustomerDetailsView.AllowPaging = true;
if (e.CancelingEdit)
{
MessageLabel.Text = "Update canceled.";
}
else
{
MessageLabel.Text = "Update completed.";
}
break;
case DetailsViewMode.Insert:
// Cancel the mode change if the DetailsView
// control attempts to transition to insert
// mode.
e.Cancel = true;
break;
default:
MessageLabel.Text = "Unsupported mode.";
break;
}
}
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>DetailsViewModeEventHandler Example</title>
</head>
<body>
<form id="form1" runat="server">
<h3>DetailsViewModeEventHandler Example</h3>
<asp:detailsview id="CustomerDetailsView"
datasourceid="DetailsViewSource"
datakeynames="CustomerID"
autogeneraterows="true"
autogenerateeditbutton="true"
allowpaging="true"
onmodechanging="CustomerDetailsView_ModeChanging"
runat="server">
</asp:detailsview>
<br/><br/>
<asp:label id="MessageLabel"
forecolor="Red"
runat="server"/>
<!-- This example uses Microsoft SQL Server and connects -->
<!-- to the Northwind sample database. Use an ASP.NET -->
<!-- expression to retrieve the connection string value -->
<!-- from the web.config file. -->
<asp:sqldatasource id="DetailsViewSource"
selectcommand="Select [CustomerID], [CompanyName], [Address],
[City], [PostalCode], [Country] From [Customers]"
updatecommand="Update [Customers] Set
[CompanyName]=@CompanyName, [Address]=@Address,
[City]=@City, [PostalCode]=@PostalCode,
[Country]=@Country
Where [CustomerID]=@CustomerID"
connectionstring=
"<%$ ConnectionStrings:NorthWindConnectionString%>"
runat="server"/>
</form>
</body>
</html>
<%@ Page language="VB" autoeventwireup="false" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">
Sub CustomerDetailsView_ModeChanging(ByVal sender As Object, ByVal e As DetailsViewModeEventArgs) Handles CustomerDetailsView.ModeChanging
' Use the NewMode property to determine the mode to which the
' DetailsView control is transitioning.
Select Case e.NewMode
Case DetailsViewMode.Edit
' Hide the pager row and clear the Label control
' when transitioning to edit mode.
CustomerDetailsView.AllowPaging = False
MessageLabel.Text = ""
Case DetailsViewMode.ReadOnly
' Display the pager row and confirmation message
' when transitioning to edit mode.
CustomerDetailsView.AllowPaging = True
If e.CancelingEdit Then
MessageLabel.Text = "Update canceled."
Else
MessageLabel.Text = "Update completed."
End If
Case DetailsViewMode.Insert
' Cancel the mode change if the DetailsView
' control attempts to transition to insert
' mode.
e.Cancel = True
Case Else
MessageLabel.Text = "Unsupported mode."
End Select
End Sub
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>DetailsViewModeEventHandler Example</title>
</head>
<body>
<form id="form1" runat="server">
<h3>DetailsViewModeEventHandler Example</h3>
<asp:detailsview id="CustomerDetailsView"
datasourceid="DetailsViewSource"
datakeynames="CustomerID"
autogeneraterows="true"
autogenerateeditbutton="true"
allowpaging="true"
runat="server">
</asp:detailsview>
<br/><br/>
<asp:label id="MessageLabel"
forecolor="Red"
runat="server"/>
<!-- This example uses Microsoft SQL Server and connects -->
<!-- to the Northwind sample database. Use an ASP.NET -->
<!-- expression to retrieve the connection string value -->
<!-- from the web.config file. -->
<asp:sqldatasource id="DetailsViewSource"
selectcommand="Select [CustomerID], [CompanyName], [Address],
[City], [PostalCode], [Country] From [Customers]"
updatecommand="Update [Customers] Set
[CompanyName]=@CompanyName, [Address]=@Address,
[City]=@City, [PostalCode]=@PostalCode,
[Country]=@Country
Where [CustomerID]=@CustomerID"
connectionstring=
"<%$ ConnectionStrings:NorthWindConnectionString%>"
runat="server"/>
</form>
</body>
</html>
Comentários
O ModeChanging evento é gerado quando um DetailsView controle tenta alterar entre o modo de edição, inserção e somente leitura, mas antes que o modo seja realmente alterado. Isso permite que você forneça um manipulador de eventos que executa uma rotina personalizada, como configurar o DetailsView controle para um modo específico ou cancelar a alteração de modo, sempre que esse evento ocorrer.
Ao criar um DetailsViewModeEventHandler delegado, você identifica o método que manipulará o evento. Para associar o evento ao manipulador de eventos, adicione uma instância do delegado ao evento. O manipulador de eventos é chamado sempre que o evento ocorre, a menos que você remova o representante. Para obter mais informações sobre delegados do manipulador de eventos, consulte Manipulando e levantando eventos.
Métodos de Extensão
| GetMethodInfo(Delegate) |
Obtém um objeto que representa o método representado pelo delegado especificado. |
Aplica-se a
Confira também
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